some animals are scarce and some animals are plentiful. we worry about animals going extinct, endangered species. here's the puzzle. if you want to save an animal which encourage people to edith? you would think -- john: donated. >> but if you can make a profit from eating it, that creates the incentive, and if you can prioritize the ownership that creates an incentive to take care of it and grow. as a result there is plenty of turkey, but you chicken, and other animals are scarce because there is no incentive, unfortunately to take care of them. john: both humans and hot seat taken, but the more hawks the fewer chickens, the more seamen's the more chickens. >> that was an inside of henry george, early economist. he understood that this nature, more hawks, they eat the chickens. come deplete the population. if we get numerous more chickens . that is the power of incentives. john: breed chickens.